Core box vent



June 15, 1965 K. R. MOINTYRE 3,188,701

CORE BOX VENT Filed Dec. 18, 1962 I V 2a INVENTOR Kim/wry 6 Ala/NW2:

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47 Toe/V556 United States Patent 3,188,701 CORE BOX VENT Kenneth R. McIntyre, Los Angeles, Calif. (8628 Lavela Ave., Whittier, Calif.) Filed Dec. 18, 1962, Ser. No. 245,503 1 Claim. (Cl. 2213) in positions which will do the most good in obtaining sound cores. In this regard, when a blast of airborne sand is received by the core box, the air must be rapidly vented while the sand remains entrapped within the core box cavity. For each specific core box design, the core box vents are located in positions which encourage the complete filling of the core box, for adequate mold density, and such vents must also be capable of maintaining an 'unclogged state for allowing air to escape.

Unfortunately, the various core box venting apparatus heretofore available for accomplishing the above objectives have all suffered from one or more deficiencies tending to limit core box operating efficiency. Primary among these difliculties has been the tendency for such venting arrangements to clog up in a short period of time, i.e., a single Working day or less. In such instances,

the vents or screens must be removed from the core box and cleaned, the latter resulting in a considerable amount of down time with consequent loss of production efficiency.

Additional difficulties encountered with core box vents have been the lack of ability to withstand the high temperatures used in baking a core, the diificulty of installing the vents in the core box, lack of structural strength and consequent vent distortion, the tendency for vent plugs and the like to pop out of the core box surface, and the expense of manufacturing such core box venting devices.

The importance of providing proper venting in core boxes cannot be overemphasized, since improper venting frequency results in the sand not being packed firmly enough in the core box cavity, with consequent inadequacy of mold density. This results in a spongy core which, when used in a casting operation, will produce castings with poorly finished surfaces and which often must be scrapped.

Accordingly, it is an object of the present invention to provide a new and improved core box vent which overcomes the above and other disadvantages of the prior art.

Another object is to provide a new and improved core box vent providing non-clogging release passages for gas escape.

A further object of the invention is the provision of a new and improved core box vent which is simple and rugged in construction, economical of manufacture, and efficient in operation.

Still another object is to provide a new and improved core box vent which is easily installed or removed from the core box and which will not pop out.

Yet another object of the present invention is the provision of a new and improved core box vent capable of withstanding the high temperatures of a core baking process and which will not distort during use.

The above and other objects and advantages of this invention will be better understood by reference to the following detailed description, when considered in con- 3,188,701 Patented June 15, 1955 "ice nection with the accompanying drawings of an illustrative embodiment thereof, and wherein:

FIGURE 1 is a fragmentary sectional view illustrating a typical core box vent installation in accordance with the present invention;

FIGURE 2 is a right-side elevational view of the vent installation of FIGURE 1 and shows the socket for mounting the vent;

FIGURE 3 is a perspective view of a core box vent in accordance with the invention;

FIGURE 4 is an enlarged sectional view, taken along the line 44 of FIGURE 3, and illustrates the reverse funnel action which prevents clogging of the vent by core box sand.

Referring now to the drawings, and particularly FIG- URES l and 2 thereof, a core box vent in the form of a plug 10 is shown installed in the wall 12 of a core box. The plug 14 has a generally circular, cylindrical appearance providing a front face 14 and a rear face 15. The front face 14 of the plug 10 is directed into the core box to receive the blast of sand and air within the core box cavity.

Adjacent the front face 14, the plug 10 is provided with an integral, peripheral flange 16 of uniform axial thickness and adapted to mate with a corresponding countersunk seat 1'7 in the core box wall 12. The remainder of the plug 10, between the rear surface of the flange 16 and the rear face 15 is threaded, as at 18, and is adapted to engage corresponding threads in the plug mounting hole. The helical thread is continuous to the point where it intersects the flange 16, as shown in FIGS. 1 and 4.

As best observed in FIGURE 2, the plug 10 is provided with a central, coaxial socket 20 extending into the plug body from the rear face 15. The socket 20 has a uniform polygonal cross section along its length, e.g., the hexagon hown in FIGURE 2, so that the socket may receive a tool of the Allen wrench variety for rotating the plug within its mounting hole during installation and removal.

The plug 10 is installed from the inside of the core box. The wrench (not shown) is inserted from the outside of the core box, through the plug mounting hole, and into the socket 20 of the plug 10. The wrench is then rotated to draw the plug 10 into the core box wall 12, until further motion of the plug is inhibited by seating of the peripheral flange 16 in the counter-sunk seat 17 of the core box Wall. Installation of the plug 10 in this manner is not only simple and reliable, but the flange 16 and seat 17 also provide positive means for preventing the plug 10 from popping out of the core box when the plug is struck by the high pressure blast of sand and air. Moreover, the flange and seat arrangement perm-its precise, flush alignment of the front face 14 of the plug 14 with the inner surface of the core box wall 12, so that a relatively smooth surfaced core can be produced.

The plug 10 is preferably manufactured by casting, to facilitate mass production at low cost. Moreover, the plug 10 is preferably fabricated of a high temperature material, such as brass or the like, so that the plug can withstand the high temperatures frequently encountered during the baking of cores within the core box.

Referring now additionally to FIGURES 3 and 4, it will be observed that the front face 14 of the plug 10 is provided with a plurality of slotted apertures 22 defined by a plurality of parallel ribs 24 and a transverse rib 26. Each of the ribs 24 is made sufiiciently wide and deep to provide a relatively rigid structure with minimal tendency to distort under the high pressure of the sand and air blast. The transverse rib 26, intersecting all of the ribs 24 at as by the appended claim.

right angles, serves to further brace the rib and aperture. 2

latticework against distortion. 2

As best observed in FIGURE 4, the sides 28 of each rib 24 are tapered to present 'a rib of progressively narrowingwidth proceeding into the plug 10 away from the front face 14. 'The effect of these tapering ribs isto pro- Vide the slots '22 with aprogressively widening cross sec- "tion proceeding into the plug 10, away from the surface 14 -in FIGURE 4, Hence, the slots 22 provide a plurality'of pyramidaL'small reverse funnels, so that the resistance of 10 the slots to passage of material therethrough is progres- I 'sively decreased in proceeding inwardlyfrorn the front face 14 to the rear face 15 through the core box wall 12 in FIGURE 1. In this connection, the plug 10 is selfcleaning, since any sand which may lodge in the portions of the slots 22 nearer the front face 14 will be cleared through the slots to the outside of the corebox by the next blast of air escaping through these slots from the interior of the core box. a

The core box'vent of the present invention satisfies a long-existing need in the casting'art for inexpensive, efii- 'cient, easily installed, non-distorting and non-clogging venting devices. 3 It will be apparent from the foregoing that, while a particular form of my invention has been illustrated and de- "scribed, various modifications can be'made without depart ward face and a rear face, said faces being disposed a,

at right angles to the longitudinal axis ofvsaid cylindrical body;

a 4 r "an end wall adjacent to and flush with said forward faceof said plug body;

a central, polygonal, coaxial Wrench socket extending into said plug body from said rear face and terminating adjacent said end wall;

, an external, peripheral. fiangehaving a uniform thickness and being integral with'said plug body, said flange having a surface lying flush with said forward face of said plug body and said end wall;

a helical thread cast upon the external cylindrical sur- 7 face of said plug body-between the rear face of said peripheral flange and said rear face of said plug body, said threadbeing continuous to a point where it intersects said flange; and

plurality of spaced, parallel slots defined by'longitudinal-ribs in said end wall,"the side surfaces of said ribs tapering to provide progressively widening, reverse funnel openings proceeding into said plug body away from said forward. face; and areinfor'cing rib extending transverse to and intersecting said ribs in saidend wall.

References Cited by the Examiner UNITED STATES PATENTS 874,418 12/07 McEvoy 2 2 13 '2,126,097 8/38 Demmler 22 13 i 2,669,769' V 2/54 Peterson 22-13 2,789,326 4/57 Krauss 22-13 2,948,933 8/60 Mol-loy ct'al. 22-36 FOREIGN PATENTS 197,976 5/58 Austriap 317,028 /29- Great Britain.

J. SPENCER OVERHOLSER, Primary Examiner. ROBERT F. WHITE, MARCUS U. LYONS, Examiners. 

